This invention relates to a graphical user interface for testing integrated circuits.
Some semiconductor manufacturing processes test integrated circuits (ICs) while the ICs are still a part of a semiconductor wafer. This is commonly referred to as semiconductor wafer level testing (WLT). Typically, WLT involves placing a semiconductor wafer in a vacuum chuck. A probe card that has probe needles is placed in contact with a set of bond pads on each of the ICs. The probes are used to transmit electrical signals to the ICs from a set of test instruments and to receive the corresponding electrical response.
In one aspect of the invention, system includes a graphical user interface (GUI) connected to an input/output device of a computer system and one or more test instruments producing a set of electrical signals. The system also includes a probe card that has multiple probe needles used for measuring the electronic characteristics of each of the devices on a semiconductor wafer. Each device has cells. Each cell has a set of bond pads. The system also has a matrix switch and an interface conduit electrically connecting the one or more test instruments, the computer, the probe card, and the matrix switch together. The semiconductor wafer is moved so that the probe needles measure the electrical characteristics of each cell within each device selected for testing.
Other embodiments may include one or more of the following features. The user can select a test configuration by interfacing the matrix switch through the GUI. The user can also select either an automatic test mode or a manual test mode. The automatic test mode includes selecting which devices on the semiconductor wafer to test. The manual test mode includes the user setting the electrical signals of the test instruments through the GUI. The probe card transmits a set of electrical signals from each test instrument through the probe needles to each set of bond pads and generates a test result for each device that is displayed graphically on the display. The test instruments include a pulse generator and a parametric analyzer. Testing can include measuring a silicon band gap voltage. Testing can also include measuring for a capacitance.
In another aspect of the invention, a method includes selecting a test configuration using the GUI and measuring a set of electrical characteristics of each device selected for testing. Each device has cells and each cell has a set of bond pads. The semiconductor wafer is moved so that the probe needles measure the electrical characteristics of each cell within each device selected for testing.
Other embodiments may include one or more of the following features. The method can include sending a signal to activate a set of test instruments. In addition, the method may include determining if the test instruments are electrically connected. Other features can include designating if testing is an automatic test mode or a manual test mode where the automatic test mode includes selecting devices on a semiconductor wafer for testing and the manual test mode includes the user setting the electrical signals of the test instruments through the GUI. The method can also include generating an output file for all devices tested and/or graphing the data in the output file on a display. The test instruments can include a pulse generator and a parametric analyzer. Testing can include measuring a silicon band gap voltage. Testing can also include measuring for a capacitance.
In still another aspect of the invention, an apparatus includes a memory that stores executable instructions and a processor. The processor executes instructions to select a test configuration using the GUI, and measure a set of electrical characteristics of each device selected for testing. Each device has cells and each cell has a set of bond pads. The semiconductor wafer is moved so that the probe needles measure the electrical characteristics of each cell within each device selected for testing.
Other embodiments may include one or more of the following features. The apparatus includes instructions that cause the machine to send a signal to activate a set of test instruments. The apparatus also includes instructions that cause the machine to determine if the set of test instruments are electrically connected. The instructions cause the machine to designate if testing is an automatic test mode or a manual test mode. The automatic test mode includes selecting devices on a semiconductor wafer for testing. The manual test mode includes the user setting the electrical signals of the test instruments through the GUI. The instructions that cause the machine to generate an output file for all devices tested and to graph data in the output file on a display. The testing includes testing a silicon band gap voltage. The testing includes a measuring a capacitance.
In a still another aspect an article includes a machine-readable medium that stores executable instructions for testing devices on a semiconductor wafer. The instructions causing a machine to select a test configuration using the GUI, and to measure a set of electrical characteristics of each device selected for testing. Each device has cells and each cell has bond pads. The semiconductor wafer is moved so that the probe needles measure the electrical characteristics of each cell for each device selected for testing.
Other embodiments may include one or more of the following features. The article includes instructions that cause the machine to send a signal to activate a plurality of test instruments. The article also includes instructions that cause the machine to determine if the plurality of test instruments are electrically connected. The instructions cause the machine to designate if testing is an automatic test mode or a manual test mode. The automatic test mode includes selecting devices on a semiconductor wafer for testing. The manual test mode includes the user setting the electrical signals of the test instruments through the GUI. The instructions cause the machine to generate an output file for all devices tested and to graph data in the output file on a display. The test instruments include a pulse generator and a parametric analyzer. The testing includes measuring a silicon band gap voltage. The testing also includes measuring a capacitance.
Each of the aspects above have the following advantages. The method allows for the automated testing of different cells on the IC without damage to the IC or the rest of the semiconductor wafer from the probe needles. By automating the testing process with the IC, testing is done faster and components within the ICs are also tested.